This invention relates to a carriage for a machine, such as a roof support, which comprises a beam having rounded ends and encircled by an articulated track which is guided by friction in a guide path formed on the straight portion and the return ends of the beam, the track being guided without play around the rounded return ends of the beam.
Various mine working machines are known which use carriages of this type, for example a level cutting machine as described in French Pat. No. 1,118,233 or a roof support as described in German Pat. Application No. 1,139,084.
When machines of this kind have carriages of the type described above, arranged in parallel pairs, for example two upper carriages or two lower carriages of a roof support, there is a problem of how to permit slight turns to the right or left without applying excessive forces to the roof or floor, and of preventing the machine from becoming jammed in any direction.